Wednesday, March 28, 2012

2923.txt

date: Wed, 14 May 2003 10:33:03 -0600
from: Tom Wigley <wigleyatXYZxyzr.edu>
subject: Re: paleo & extremes
to: Tim Osborn <t.osbornatXYZxyz.ac.uk>

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Tim,

Thanx. I will keep in touch on the paleo stuff. Comparisons of results
is a good first goal. Different forcings and different climate
sensitivities present a bit of a challenge, but I think we can get
around that using MAGICC.

Tom.
++++++++++++++++++++++++++++++++++++++++++++

Tim Osborn wrote:
> Hi Tom,
>
> (1) the extremes reference in question appeared last year:
>
> Extreme daily precipitation in Western Europe with climate change at
> appropriate spatial scales
> M. J. Booij
> Department of Civil Engineering, University of Twente, PO Box 217, 7500
> AE Enschede, The Netherlands
> email: M. J. Booij (m.j.booij@sms.utwente.nl)
>
> International Journal of Climatology
> Volume 22, Issue 1, 2002. Pages: 69-85
>
> I'm not sure which other references you would be particularly wanting -
> obviously this is a big subject area. We have a useful list of some of
> them on one of our webpages:
> http://www.cru.uea.ac.uk/projects/mice/html/extremes.html#references
>
> Also see these (need to make your font pretty big to read these!):
> http://www.met.rdg.ac.uk/~han/Extremes/bib0.html
> http://www.met.rdg.ac.uk/~han/Extremes/bib1.html
>
> (2) HadCM3 run for 1500-2000 under natural only forcings is complete.
> 1750-2000 under "all" forcings is almost complete (its into the 20th
> century). I did email Caspar in January asking whether there is
> interest in comparisons across the models (we also have
> ECHAM4/HOPE[==ECHO-G] runs in our EU project SO&P), but I didn't get a
> response. Multi-model comparisons might be interesting to do still
> (though SO&P partners were keen to keep the initial focus within our
> project just on HadCM3 and ECHO-G). Is that why you were asking,
> because of possible comparisons that might be made? As to the forcings,
> I agree that the volcanic forcings used could be better, but we were to
> some extent constrained by our wish to have very similar forcings in
> HadCM3 and ECHO-G and the ECHO-G runs were begun about 2 years ago I
> think! The solar forcing is also of concern - did you use the Lean et
> al. estimates for that? While there are clearly some big uncertainties,
> from what I understand there is qualitative (at least) agreement with
> 14C and 10Be records. Presumably MAGICC (or similar) could help to
> quantify the global/hemispheric scale differences due to forcing
> uncertainties? I'm keen to keep collaborative links open on these
> issues (though subject to agreement with my SO&P partners, of course),
> so if you have any specific analyses/comparisons that we could work on
> together (or involving Sarah) then let me know.
>
> Cheers
>
> Tim
>
> At 21:18 13/05/2003, you wrote:
>
>> Tim,
>>
>> I thought you might be able to tell me how the Hadley paleo runs are
>> going. We (Caspar Ammann et al.) have completed a run from 1000AD to
>> the present using the paleo version of CSM (slightly poorer resolution
>> that the standard CSM). The results are quite interesting. I believe
>> we are using a better volcano record (Caspar's) than anyone else.
>> Solar is tricky -- the astronomical basis for Judith Lean's low
>> frequency irradiance reconstruction has been shot down as you probably
>> know.
>>
>> One of the nice results is that we can use MAGICC to back out the
>> signal from the noise. Sarah has some material that I sent her showing
>> that MAGICC can simulate both volcanic responses (on a monthly to
>> century time scale) and solar responses (annual to century) with
>> extremely high fidelity. Ask her to show you.
>>
>> On another matter, you showed me a paper some time back on extreme
>> value distributions, which I think you were refereeing. There was an
>> earlier paper on the same subject by the same author. Can you give me
>> the references -- and any other relevant items dealing with the
>> modeling of changes in the frequency of extremes?
>>
>> Best wishes,
>> Tom.
>
>
> Dr Timothy J Osborn | phone: +44 1603 592089
> Senior Research Associate | fax: +44 1603 507784
> Climatic Research Unit | e-mail: t.osbornatXYZxyz.ac.uk
> School of Environmental Sciences | web-site:
> University of East Anglia __________| http://www.cru.uea.ac.uk/~timo/
> Norwich NR4 7TJ | sunclock:
> UK | http://www.cru.uea.ac.uk/~timo/sunclock.htm
>
>
>


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